Brady Barr

Reptile expert Brady Barr plunges to frigid ocean depths to get close up to one of the world's most mysterious, deep-sea sharks—the giant sixgill shark. These prehistoric creatures have remained elusive despite their size, but while filming some of the largest congregations of sharks ever seen, Barr and his team make an amazing observation and capture unique shark behavior on film.

Brady's met plenty of deadly snakes, but now he's traveling the globe to hunt down seven of the world's most dangerous snakes.

Brady Barr tests a new laser cam that can measure animals from a distance by personally capturing and measuring each beast in the search.

Piranhas - the stuff of nightmares and legends. They're infamous for how fast they can devour prey, and are known to attack in groups of up to 100. National Geographic joins a team of scientists heading to the Amazon to investigate a piranha mystery of immense proportions. A fossil of a giant jaw fragment has been identified as an ancient piranha, but with a terrifying twist: the tooth belonged to a fish seven times the size of existing piranha species.